1. Field of the Invention
This invention relates generally to wireles and long distance carriers, Internet service providers (ISPs), and information content delivery services/providers and long distance carriers. More particularly, it relates to location services for the wireless industry.
2. Background of Related Art
It is desired to accurately locate cell phones within a cellular network. While there are several techniques for determining location in a mobile device, a future generation of mobile phones may include a global positioning satellite (GPS) receiver chipset, thus having the ability to locate itself via GPS.
FIG. 6 depicts the conventional Global Positioning Satellite system including about 24 or more GPS satellites.
In particular, as shown in FIG. 6, the earth 200 is surrounded by approximately 24 GPS satellites 101-124, which each have their own rotational orbit about the earth 200. There are currently about 24 to 27 GPS satellites in the GPS network, each moving about the earth approximately 6 times each day.
Unfortunately, as the phone moves about the country, locations with respect to satellites change. Thus, GPS devices attempting to determine their position with respect to the earth 200 will only be able to communicate with a smaller number of the total GPS satellites at any one time.
The time required for lock in and location determination by a conventional GPS receiver in determining which of the GPS satellites in the GPS network takes several minutes, and as many as 5 or 6 minutes for a standard GPS receiver, which is longer than many if not most phone calls.
There is a need for a less cumbersome and more efficient technique for using GPS location information in a highly mobile and fast paced society.
In accordance with one aspect of the present invention, a culled satellite list comprises identification of no more than four GPS satellites within a preferred area above a particular region that a subscriber is to attempt communications with. The culled satellite list relates to GPS satellites preferred for use by subscribers within a particular region.
A method of allowing fast location determination by a mobile device in a wireless system in accordance with another aspect of the present invention comprises receiving ephemeris data regarding a GPS satellite network. A culled satellite list of no more than four GPS satellites is determined for use by mobile devices in the wireless system. The culled satellite list information is communicated to the mobile device.